Trisazo dyes for cotton and process of making the same



Patented Mar. 20,1928.

.UNITED STATES PATENT OFFICE.

HENRY JORDAN, OF WILMTNGTON, DELAWARE, ASSIGNOR TO E. I. DU PONT DE NE- MOU RS 85 COMPANY, OF WILMINGTON, DELAWARE, A CORPORATION OF DELA- WARE.

TRISAZO, .DYES FOR COTTON AND PROCESS OF MAKING THE SAME.

No Drawing.

This invention relates to trisazo dyes for cotton and to the method of preparing the same. More particularly it is concerned with improved blue and gray dyes and their preparation by coupling a iazo compound of the benzene or naphthalene series not containing a free hydroxyl group to an alpha-amino naphthalene compound without a free hydroxyl group, diazotizing the intermediate amino azo dye, coupling it again to the same or another alpha-amino naphthalene compound, then diazotizing the resulting disazo R, representing a benzene or naphthalene derivative without a free hydroxyl group, R and R representing naphthalene derivatives without a free hydroxyl group and R, representing an acidyl 2-1mino-8-naphthol-6- sulphonic acid. I

The new dye compounds and their preparation can best be disclosed by the presentation of a number of examples of actual embodiments thereof. It is to be understood,

of course, that these examples are furnished below by wa of-illustratlon only, and that the details 0 procedure specified therein, as well as the particular proportions, reagents, temperatures, etc'., therein disclosed are susceptible of variation and substitution.

The examples follow:

Example 1.

173 parts of para sulphanilic acid are diazotized in the normal Way and coupled to 223 parts of mixed Cleves acid in the pres- On reducing the dye with stannous chloride -N ..N- -8N-N oma OINs "Application filed August 10, 1926. Serial No. 128,519.

ence of-a quantity of sodium acetate sufficient to neutralize the mineral acid reaction. The coupling temperature should be 1520 C. After about one hours stirring hydrochloric acid is added in a sufficient amount to diazotize with 69 parts of sodium nitrite.

The temperature of the diazo should be 15-20". After about 40 minutes stirring the diazotization will be complete and there is added now'a soluton of 143 parts of alpha naphthylamine in 2500 parts of water and 150 parts of a 31% hydrochloric acid solution, keeping the temperature of the coupling at about 20. The mixture is stirred about 12' hours when the coupling will be complete. It is heated to 70, salted out and filtered. The acid paste is stirred up with 6000 parts of water, heated to 70, converted to the sodium salt by addition of sodium hydroxide. 69 parts of sodium nitrite are added to the solution, and thenthe mixture is run into a hydrochloric acid solution containing enough ice to keep the temperature below 10 C. There must be suflicient hydrochloric acid to keep the reaction mineral acid. After A hours stirring the diazotization is run into a solution of 281 parts of 2-acetyl-amino-8-naphthol-6-sulphonic acid, containing enough soda ash to keep the reaction alkaline until the end of the coupling. The coupling is then heated to 80, salted out and filtered. In its dry ground form it is a dark powder with a bronzy lustre, soluble in water with a bluish-violet color, inconcentrated sulfuric acid with a greenish gray color. It dyes cotton in bluish gray shades, which show a good fastness to washing and an excellent fastness to.light. The dyeings give a perfect white discharge withdiydro sulphite. On mixed cotton-silk fibres dyed from a neutral Glauber salt bath it leaves the silk practically unstained. The new dye will have the following formula:

NH.COCH:

the following compounds will be obtained:

p-sulphanilic acid, 1-4 naphthylene diamine- 6-sulphonic acid, 1-4 naphthylene diamine, 2-acetyl amino-7-amino-8-naphthol-6-sulfonic acid.

Example 2.

Substituting in Example 1 the 173 parts of p-sulphanilic acid by 303 parts of 2-naphthylamine-6-8-disulfonic acid and having all other conditions the same, a dye is ob tained of similar properties as the one in Example 1, the solution in water being of a bluish gray coloration, soluble in concentrated sulfuric acid with a bluish green color dyeing cotton a trace greener than the dye in Example 1.

This dye will yield on reduction with stannous chloride the same compounds as those mentioned in Example 1, except instead of p-sulphanilic acid, 2-naphthylamine-6-8-disulfonic acid is obtained. a Using 2-benz0yl amino-8-naplfthol6-sulfonic acid instead of the acetyl compound a slightly redder shade gray is obtained.

Ewample 3.

Using in Example 2 as second component alpha naphthylamine instead of Cleves acid and asthird component 1-6-Cleves acid instead of alpha naphthylamine, leaving all other conditions the same, a dye is obtained which dyes cotton in blue shades, having similar properties as the gray dye of Examalpha-naphthylamine and Cleves acid, there may be used, for example, derivatives of these compounds not having a free hydroxy group, such as 1-amino-2-naphthol ether or its 6 or 7 sulphonic acid.

By the term free hydroxy group as employed throughout the specification, I mean a hydroxy group attached to the nucleus. Consequently a compound not containing a free hydroxyl group is a compound having no hydroxyl group attached to the nucleus of the same.

When Oleves acid is referred to in the claims, I intend to designate either 1:6

' naphthyl-amine-sulfonic acid or 1:7 naphthylamme-sulfonic acid or a mixture of both. By suitably yarying the components and using appropriate proportions and conditions, a large number of valuable blue to .gray trisazo dyes for cotton may be presulting amino azo intermediate, coupling the resulting diazo azo compound to a second alpha-aminio-naphthalene compound having no free hydroxy group, diazotizing the resulting disazo compound and finally coupling to a 2-acyl-amino-8-naphthol-6-sulphonate.

2. The process of producing a trisazo d e which comprises coupling a diazo-azo-nap thalene compound having no' free hydroxy group to an alpha-amino-naphthalene compound having nov free hydroxy group, diazotizing the resulting disazo compound and finally coupling to a 2-acyl-amino-8-naphthol-(i-sulphonate.

3. The process of producing a trisazo dye which comprises coupling a diazo disazo compound having no free hydroxy group to 2-acyl-amino-8-naphthol-6-sulphonate.

4. The process as set forth in claim 1 wherein the acyl-amino-naphthol sulfonic acid is 2-acetyl-amino-8-naphthol-6-sulphonate.

5. The process set forth in claim 1 wherein the first amino=naphthalene compound is Cleves acid.

6. The process set forth in claim 1 wherein the second amino-naphthalene compound is alpha-naphthylamine.

7. The process set forth in claim 1 wherein the aryl diazo compound is the diazo compo nd of 2-naphthylamine-68-disulphonic aci 8; A compound having the general formula:

R N=l TR,N=NR,-N=N--R inwhich R represents an aryl radical having no free hydroxl group, R and R represent naphthalene derivatives without a free hydroxyl group, and R represents a 2-acylamino-8-napht ol-6-sulphonate.

9. A compound havmg the general formula:

R,N=NR N=NR -N=NR in which R represents an aryl radical having no free hydroxyl group, R and R represent naphthalene derivatives without a free hydroxyl grou and R represents a 2-acetylamino-8-napht ol-6-sulphonate.

10. The compound set forth in claim 8 wherein R represents a sulfonated benzene or naphthalene group.

11, The compound set forth in claim 8 wherein R represents a naphthaleneradical' wherein R represents a naphthalene 6-8-dihaving no substituents other than the azo sulphonicacid group. oups.

12. The compound set forth in claim 8 14. A textile material dyed with wherein R represents a sulfonated naphpound set forth in claim 8. thalene group. In testimony whereof I aflix my signature.

13. The compound set forth in claim 8 HENRY JORDAN.

the com- 

